1. Field of the Invention
This invention relates, broadly speaking, to a novel internal combustion engine and to a novel piston assembly therefor.
More particularly, this invention relates to a novel two-cycle internal combustion engine and to a novel compound piston assembly therefor.
2. Description of the Prior Art
Two-cycle internal combustion engines have long been known, sold and used. None, to the knowledge of the present inventor, embody the particular novel design of the present invention.
Pistons for internal combustion engines have long been known, sold and used. None, to the knowledge of the present inventor, embody the novel design of the compound piston assembly of the present invention.
One of the objects of the present invention is to provide an improved two-cycle internal combustion engine which, with an improved piston assembly, has fewer parts than conventional two-cycle internal combustion engines and is therefor more economical to construct, and which is more efficient to operate than presently available two-cycle internal combustion engines.
Another of the objects of this invention is to provide an improved two-cycle internal combustion engine in which the piston in one of the cycles drives, and alternatively in the other of the cycles is driven by, a swash plate (also known as a wobble plate) connected to the drive shaft, and in another embodiment by a rod operatively connected to a cam on the drive shaft.
Yet another of the objects of this invention is to provide a dual two-cycle engine assembly in which two of the novel engines of this invention may be opposed in opposition against a single interposed swash plate.
Still other and further objects of the present invention will become apparent by reference to the accompanying specification and drawings, and to the appended claims.
Briefly, the foregoing objects are attained by providing a two-cycle internal combustion engine comprising a cylinder, a cylinder head mounted within the cylinder, and a compound piston assembly comprising a small diameter piston slidably engaging through piston rings a bore in the cylinder head, and a large diameter hollow piston slidably engaging through piston rings the inside wall of the cylinder. The drive shaft of the engine extends through the hollow large diameter piston and through a bore extending through the small diameter piston of the compound piston assembly. A swash plate secured to the drive shaft engages roller bearings rotatably mounted to and inside the hollow large diameter piston of the compound piston assembly. The compound piston assembly moves, or is moved depending upon the particular cycle of the operation, longitudinally within the cylinder by contact through the roller bearings with the swash plate. Rotation of the swash plate causes, or is caused by, rotation of the drive shaft. Approriate apertures are provided in the cylinder and in the cylinder head for introduction of a fuel/air mixture and for the discharge of exhaust gases. In an alternative embodiment, the drive shaft is provided with a cam portion engaging a crank which extends into the hollow large diameter piston of the compound piston assembly. A rod mounted to and within the hollow large diameter piston extends through an aperture in the crank. Longitudinal movement of the crank causes, or is caused by, longitudinal movement of the compound piston assembly within the cylinder, and by virtue of the cam portion on the drive shaft, rotation of the drive shaft results. In this embodiment, the drive shaft does not extend through a bore in the small diameter piston of the compound piston assembly, but rather through lateral apertures in the cylinder wall. In yet another embodiment, two engines of similar construction are arranged in opposition about a single swash plate. The hollow large diameter pistons of their respective compound piston assemblies engage, through their respective roller bearings, opposite sides of the single interposed swash plate which is secured to a drive shaft extending through the hollows of their respective large diameter pistons and through bores in their respective small diameter pistons.